MA^ 2 189- 



X.lTi'RJi 



The last section to which \vc would call attention is 

 that which contains a description of a theory to explain 

 nhy sonic plants arc adapted for direct fertilisation, and 

 others for crossed fertilisation, .-\ccordinj; to this theory, 

 intomophilous plants ha\e to make certain sacrifices in 

 order to attract visitors in the shape of the substances 

 needed in the formation of nectar and \arious perfumes, 

 which are, to a large extent, drawn from the reser\e- 

 inaterials contained in the ])lant at the time of flowering, 

 if these reserve-materials are present in considerable 

 quantities, the plant w ill be able to produce much nectar, 

 ^c. and will attract many insects, and become adapted 

 10 crossed fertilisation. If, on the other hand, it has 

 Imt little of these stores, it will be able to expend \ery 

 little in attracting insects, but will have to keep the 

 great part of its scanty stores for the maturation of its 

 fniits and seeds. The consequence will be that the 

 tlowers of these latter plants will be but little visited by 

 insects, and will become adapted to self-fertilisation. 

 The author, while he admits that this theory is insuffi- 

 cient to explain certain observations, \et maintains that 

 it is more general in its application than Warming's 

 ulea expressed with regard to the flora of Greenland. 

 .\ccording to this latter author, crossed fertilisation may 

 be considered the rule in the case of those plants which 

 multiply rapidh' by vegetative reproduction, while plants 

 without this second method of reproducing their kind, 

 •md which must necessarily bring their seeds to maturity, 

 are most usually adapted to self-fertilisation. It is. how- 

 ever, most probable that neither of these theories should 

 be regarded as in itself giving all the determining causes 

 for a plant becoming adapted to crossed or self-fertili- 

 sation, but as only expressing two of, it may be, many 

 factors which are at work in moulding any given plant 

 for one form of fertilisation or another. H. H. I). 



firessions iViiti Bolanistc. 

 Libraire Fischbacher."; 



OUR HOOK SHEI.F. 



A travcrs Ic Caucasc. 

 8vo. pp. 



.\titLS et Im- 

 348. (Paris : 



l)lv. Ll'.viKK accompanied his botaniial friend, .Signor 

 .Stephen Sonmiicr, on a tour through the Central Caucasus 

 in 1890, the object being mainly to collect and study the 

 ilora of the mountains. The letters which he sent to his 

 friends recording his impressions were published in a 

 n\agazine without his knowledge, although not written for 

 the public, and the present volume is practically a re- 

 publication of the letters, edited by the author, and 

 illustrated by numerous sketches and re|)roductions of 

 photographs. Amongst the latter are several of .Signor 

 \'ittorio .Sella's tine pictures of Caucasian scenery, which, 

 lunvever, arc not done justice to in the process blocks. 

 The botanical results of the journey have been ])ublished 

 for the most |)art in the lUiUctin of the Italian Botanical 

 Society, and only a list of the sixty-nine new species found 

 is given in the book, such references to botany as occur in 

 the text, though full of interest and presenting some acute 

 :.;eneralisations, by no means preponderating over the 

 miscellaneous observations of an intelligent tourist, and 

 the pleasantly narrated incidents of travel. A list of 

 thirty-seven species of lepidoptera collected by Dr. I.evier 

 is also given. 



The two botanists were accompanied by an Italian 

 [leasant as hunter, cook and general assistant ; and 

 together they experienced few difficulties and no danger 

 "11 their journeys through unfrequented regions for four 



NO. I 33 I, VOL. 52 I 



months, .'\ftcr some excursions in the neighbourhood of 

 Batuni and of Tiflis. they started from Kutais for the 

 journe\- across the range, going up the valley of the 

 Rion and across the Latpari Pass into Swanetia. After 

 traversing the valleys of .Swanetia and Abkhasia, and 

 making an excursion up the valley of the Kukurtli cm the 

 western slope of Elburz. they reached the northern plain 

 by the valley of the Kuban. They returned to Tiflis by the 

 coach road from \'ladika\kas through the Dariel Pass 

 hea\ily laden with more than ten thousand botanical 

 specimens, the drying of which was a never-failing source 

 of surprise and amusement to natives and Russian 

 officials alike. 



The spirit of holiday and nature-worship brejithes 

 through the whole book. Rarely, we belie\e, is a traveller 

 in untrodden ways so able to appreciate to the full the de- 

 lights of his surroundings as this light-hearted Swiss 

 physician, whose high spirits and good-humour retain 

 contagious qualities even through the pages of his book. 



H. R. M. 



Science Readers. By \incent T. .\lurche. Books i, to 

 iii. (London : Macmillan and Co., 1895.) 



Ix elementary schools where the rudiments of knowledge 

 about properties and things are taught, these books may 

 be introduced with advantage as reading books. The 

 style is conversational, and every effort appears to 

 have been made to con\e)' the information in simple 

 language, as well as to make it interesting. 



LETTERS TO THE EDITOR. 



[ The Edito}- docs not fio/d himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return^ or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of NATtTRE. 

 No notice is taken of anonymous comviunications.'\ 



Origin of the Cultivated Cineraria. 



Ix the recent discussion at the Royal Society, I used as an 

 illustration of the amount of variation which could he brought 

 about under artificial conditions in a limited time, the case of 

 Cineraria eruenta. which I regarded as having given rise to 

 the cultiv,ate(l Cineraria. 



This Mr. Hateson describes as *' misleading." 

 I havf read all he has to say, and. with the assistance of com- 

 petent members of my staff, have carefully examined authentic 

 specimens of all the species he names as having had a share in 

 the parentage of the Cineraria. 



Those species, if I understaml him rightly, are four in num- 

 ber : eruenta, aurita, popttlifolia and lanata. They were all 

 introduced into English horticulture, through Kew, lietween 

 1777 and 17S0, and were figured and described by L'Heritier in 

 his " Sertum .^nglicunl." 



A technical discussion of the subject would necessarily take 



up a good deal of space, and would not be very interesting to 



readers of Natiirk. Mr. B.ateson refers to Ue Gmdolle's 



•' Prodromus." It will Iil- sufficient, perhaps, to say that had 



he studied that authority with care, he would have found 



that while crucnia is, like the modern Cineraria, herbaceous, 



aurita, populifolia and lanata are shrubby species. Further, 



while the modern Cineniria retains the exact foliage of cruen a, 



tliat of aurita and populifolia resembles the foliage of the white 



poplar ; " folia populi allxv." Apart from the additional 



fact that populijolia has yellow flowers, I think I may 



confidently ap|ieal to even the non-botanical eye as to whether 



the modern Cineraria exhibits anything of the white [xiplar 



i character about it. As to lanata, its general .asiKCt is sufli- 



j ciently indicated by its specific name. It is represented 



by numerous specimens in No. 4 House at Kew, where Mr. 



I B.ateson may inspect il. He will probably then regret, for the 



i sake of his reputation as a naturalist, that he committed himself 



to print on a subject on which he evidently posses-ses little 



objective knowledge. 



I may add that in the discussion at the Royal Society, Mr. 

 Baleson as.serted to my surprise that the cultivated varieties ol 

 the Camellia could he distinguished by their leaves alone. 1 



